Avoid missing symbol errors when building JITLinkTests for windows
shared library builds with explicit symbol visibility macros are
enabled.
This is part of the work to enable LLVM_BUILD_LLVM_DYLIB and LLVM
plugins on window.
x86_64::GOTTableManager and x86_64::PLTTableManager will now look for existing
GOT and PLT sections and re-use existing entries if they're present.
This will be used for an upcoming MachO patch to enable compact unwind support.
This patch is the x86-64 counterpart 42595bdaefb, which added the same
functionality to the GOT and PLT managers for aarch64.
Block::edges_at is a convenience method for iterating over edges at a given
offset within a jitlink::Block.
This method will be used in an upcoming patch for compact unwind info support.
Adds new convenience methods findDefinedSymbolByName, findExternalSymbolByName
and findAbsoluteSymbolByName to the LinkGraph class. These should be used to
find symbols of the given types by name.
COFFLinkGraphBuilder and MachOPlatform are updated to take advantage of the
new methods.
aarch64::GOTTableManager and aarch64::PLTTableManager will now look for
existing GOT and PLT sections and re-use existing entries if they're present.
This will be used for an upcoming MachO patch to enable compact unwind support.
Use SymbolStringPtr for Symbol names in LinkGraph. This reduces string interning
on the boundary between JITLink and ORC, and allows pointer comparisons (rather
than string comparisons) between Symbol names. This should improve the
performance and readability of code that bridges between JITLink and ORC (e.g.
ObjectLinkingLayer and ObjectLinkingLayer::Plugins).
To enable use of SymbolStringPtr a std::shared_ptr<SymbolStringPool> is added to
LinkGraph and threaded through to its construction sites in LLVM and Bolt. All
LinkGraphs that are to have symbol names compared by pointer equality must point
to the same SymbolStringPool instance, which in ORC sessions should be the pool
attached to the ExecutionSession.
---------
Co-authored-by: Lang Hames <lhames@gmail.com>
Symbol::setSize asserts that the new size does not overflow the containing
block, so we need to point the Symbol at the correct Block before updating its
size (otherwise we may get a spurious overflow assertion).
Creation of pointers and jump stubs always succeeds for all existing JITLink
backends, and I haven't been able to think of a scenario where it would fail.
(Pointer / stub *fixup* may fail due to range errors, but that will happen
later and the APIs already account for it).
The getMachODefaultTextSection and getMachODefaultRWDataSection functions
return the "__TEXT,__text" and "__DATA,__data" sections respectively, creating
empty sections if the default sections are not already present in the graph.
These functions can be used by utilities that want to add code or data to these
standard sections (e.g. these functions can be used to supply the section
argument to the createAnonymousPointerJumpStub and
createPointerJumpStubBlock functions in the various targets).
LinkGraph::splitBlock used to take a single split-point to split a Block into
two. In the common case where a block needs to be split repeatedly (e.g. in
eh-frame and compact-unwind sections), iterative calls to splitBlock could
lead to poor performance as symbols and edges are repeatedly shuffled to new
blocks.
This commit updates LinkGraph::splitBlock to take a sequence of split offsets,
allowing a block to be split into an arbitrary number of new blocks. Internally,
Symbols and Edges only need to be moved once (directly to whichever new block
they will be associated with), leading to better performance.
On some large MachO object files in an out of tree project this change improved
the performance of splitBlock by several orders of magnitude.
rdar://135820493
Update the folder titles for targets in the monorepository that have not
seen taken care of for some time. These are the folders that targets are
organized in Visual Studio and XCode
(`set_property(TARGET <target> PROPERTY FOLDER "<title>")`)
when using the respective CMake's IDE generator.
* Ensure that every target is in a folder
* Use a folder hierarchy with each LLVM subproject as a top-level folder
* Use consistent folder names between subprojects
* When using target-creating functions from AddLLVM.cmake, automatically
deduce the folder. This reduces the number of
`set_property`/`set_target_property`, but are still necessary when
`add_custom_target`, `add_executable`, `add_library`, etc. are used. A
LLVM_SUBPROJECT_TITLE definition is used for that in each subproject's
root CMakeLists.txt.
Likely related to platform-specific expansion of gtest macros:
```
llvm/unittests/ExecutionEngine/Orc/CoreAPIsTest.cpp:1276:12: warning: suggest explicit
braces to avoid ambiguous 'else' [-Wdangling-else]
```
Specifying relocation fixup constants with name and type facilitates
readability and compile-time checks. The `FixupInfo<EdgeKind>` facade
organizes the information into entries per relocation type and provides
uniform access across Arm and Thumb relocations. Since it uses template
specializations, it doesn't limit potential entries. We cannot access
the entries dynamically though, because `EdgeKind` must be given as a
compile-time constant.
With this patch we populate a static lookup table on-demand and use it
for dynamic access in opcode-checks.
Reading implicit addend from a relocation site doesn't require a complete
`LinkGraph` edge. The operation is independent from `TargetSymbol`,
but constructing an `Edge` instance required one. This patch fixes the
inconsistency and simplifies some setup code from the error unittests.
Furthermore this patch prepares for the `Arm`/`Thumb`/`Data` helper
functions to be turned into implementation details. Exposing them in the
API causes unfortunate inconsistencies that we don't want to error-check
all the time, e.g. passing `Thumb_Call` to `readAddendArm()`.
This test checks for error paths in relocation dependent functions of readAddend and applyFixup. It is useful to check these to avoid unexpected assert errors. Currently opcode errors are triggered in most of the cases in AArch32 but there might be further checks to look for in the future. Different backends can also implement a similar test.
Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class. This patch replaces
{big,little,native} with llvm::endianness::{big,little,native}.
This patch completes the migration to llvm::endianness and
llvm::endianness::{big,little,native}. I'll post a separate patch to
remove the migration helpers in llvm/Support/Endian.h:
using endianness = llvm::endianness;
constexpr llvm::endianness big = llvm::endianness::big;
constexpr llvm::endianness little = llvm::endianness::little;
constexpr llvm::endianness native = llvm::endianness::native;
Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class as opposed to an
enum. This patch replaces support::{big,little,native} with
llvm::endianness::{big,little,native}.
The *Policy suffix came from the earlier MemAllocPolicy type, where it was
included to distinguish the type from a memory-allocation operation.
MemLifetime is a noun already, so the *Policy suffix is just dead weight now.
Add support for static Arm relocations of R_ARM_MOVT_ABS and R_ARM_MOVW_ABS_NC
which are emitted by movt and movw instructions. The implementation contains
relocation fixup and its testing as well as its encode/decode functions for
reading and writing immediate values together with its unittests.
The Windows MSVC builder complains: 'ImmMask' cannot be implicitly captured because no default capture mode has been
specified
When adding the explicit capture, Clang warns: Lambda capture 'ImmMask' is not required to be captured for this use
This seems to be a known implementation divergence. Using a default value capture should avoid the issue.
- Added WritableArmRelocation and ArmRelocation Structs
- Encode/Decode funcs for B/BL A1 and BLX A2 encodings
- Add ARM helper functions, consistent with the existing Thumb helper functions
- Add Test for ELF::R_ARM_CALL
Reviewed By: sgraenitz
Differential Revision: https://reviews.llvm.org/D157533
Creating stubs in JITLink require creating architecture-specific edges. In order to allow user to create stubs in cross-architecture manner, this patch exposes these stub creations functions by returning "stub creators" for given triple.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D155557
If JITLinkGeneric::linkPhase2 receives an Error rather than an InFlightAlloc
then we need to call JITLinkContext::notifyFailed, rather than calling
abandonAllocAndBailOut -- the latter asserts that there is an allocation to
abandon, and this was turning allocation errors into assertion failures in
debug mode.
Creating zero-filled blocks should use allocateBuffer to allocate the block's
content buffer, rather than allocateContent. (allocateContent interpreted what
would have been the size argument as a single-element ArrayRef and allocated a
single byte).
This first version lays the foundations for AArch32 support in JITLink. ELFLinkGraphBuilder_aarch32 processes REL-type relocations and populates LinkGraphs from ELF object files for both big- and little-endian systems. The ArmCfg member controls subarchitecture-specific details throughout the linking process (i.e. it's passed to ELFJITLinker_aarch32).
Relocation types follow the ABI documentation's division into classes: Data (endian-sensitive), Arm (32-bit little-endian) and Thumb (2x 16-bit little-endian, "Thumb32" in the docs). The implementation of instruction encoding/decoding for relocation resolution is implemented symmetrically and is testable in isolation (see AArch32 category in JITLinkTests).
Callable Thumb functions are marked with a ThumbSymbol target-flag and stored in the LinkGraph with their real addresses. The thumb-bit is added back in when the owning JITDylib requests the address for such a symbol.
The StubsManager can generate (absolute) Thumb-state stubs for branch range extensions on v7+ targets. Proper GOT/PLT handling is not yet implemented.
This patch is based on the backend implementation in ez-clang and has just enough functionality to model the infrastructure and link a Thumb function `main()` that calls `printf()` to dump "Hello Arm!" on Armv7a. It was tested on Raspberry Pi with 32-bit Raspbian OS.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D144083
This first version lays the foundations for AArch32 support in JITLink. ELFLinkGraphBuilder_aarch32 processes REL-type relocations and populates LinkGraphs from ELF object files for both big- and little-endian systems. The ArmCfg member controls subarchitecture-specific details throughout the linking process (i.e. it's passed to ELFJITLinker_aarch32).
Relocation types follow the ABI documentation's division into classes: Data (endian-sensitive), Arm (32-bit little-endian) and Thumb (2x 16-bit little-endian, "Thumb32" in the docs). The implementation of instruction encoding/decoding for relocation resolution is implemented symmetrically and is testable in isolation (see AArch32 category in JITLinkTests).
Callable Thumb functions are marked with a ThumbSymbol target-flag and stored in the LinkGraph with their real addresses. The thumb-bit is added back in when the owning JITDylib requests the address for such a symbol.
The StubsManager can generate (absolute) Thumb-state stubs for branch range extensions on v7+ targets. Proper GOT/PLT handling is not yet implemented.
This patch is based on the backend implementation in ez-clang and has just enough functionality to model the infrastructure and link a Thumb function `main()` that calls `printf()` to dump "Hello Arm!" on Armv7a. It was tested on Raspberry Pi with 32-bit Raspbian OS.
Reviewed By: lhames
Differential Revision: https://reviews.llvm.org/D144083
This reapplies 2cc64df0bd6a802eab592dbc282463c3e4a4281c, which was reverted in
5379c46d490640bfa80283e00240b6f1006092b4 due to bot failures.
The new patch contains fixes to ELFLinkGraphBuilder.h to better handle
non-SHT_ALLOC sections (these were being accidentally skipped in the previous
patch), and to skip SHT_NULL sections.
The original MemDeallocPolicy had two options:
* Standard: allocated memory lives until deallocated or abandoned.
* Finalize: allocated memory lives until all finalize actions have been run,
then is destroyed.
This patch introduces a new 'NoAlloc' option. NoAlloc indicates that the
section should be ignored by the JITLinkMemoryManager -- the memory manager
should allocate neither working memory nor executor address space to blocks in
NoAlloc sections. The NoAlloc option is intended to support metadata sections
(e.g. debug info) that we want to keep in the graph and have fixed up if
necessary, but don't want allocated or transmitted to the executor (or we want
that allocation and transmission to be managed manually by plugins).
Since NoAlloc blocks are ignored by the JITLinkMemoryManager they will not have
working memory allocated to them by default post-allocation. Clients wishing to
modify the content of a block in a NoAlloc section should call
`Block::getMutableMemory(LinkGraph&)` to get writable memory allocated on the
LinkGraph's allocator (this memory will exist for the lifetime of the graph).
If no client requests mutable memory prior to the fixup phase then the generic
link algorithm will do so when it encounters the first edge in any given block.
Addresses of blocks in NoAlloc sections are initialized by the LinkGraph
creator (a LinkGraphBuilder, if the graph is generated from an object file),
and should not be modified by the JITLinkMemoryManager. Plugins are responsible
for updating addresses if they add/remove content from these sections. The
meaning of addresses in NoAlloc-sections is backend/plugin defined, but for
fixup purposes they will be treated the same as addresses in Standard/Finalize
sections. References from Standard/Finalize sections to NoAlloc sections are
expected to be common (these represent metadata tracking executor addresses).
References from NoAlloc sections to Standard/Finalize sections are expected to
be rare/non-existent (they would represent JIT'd code / data tracking metadata
in the controller, which would be surprising). LinkGraphBuilders and specific
backends may impose additional constraints on edges between Standard/Finalize
and NoAlloc sections where required for correctness.
Differential Revision: https://reviews.llvm.org/D146183
Commit 10b5fec2563 uses a char -1 value, which triggers narrowing conversion
warnings / errors on some platforms (see e.g.
https://lab.llvm.org/buildbot/#/builders/36/builds/30312). Adding an explicit
conversion should fix this.
Renames the existing allocateString method to allocateContent and adds a pair of
allocateCString methods.
The previous allocateString method did not include a null-terminator. It behaved
the same as allocateContent except with a Twine input, rather than an
ArrayRef<char>. Renaming allocateString to allocateBuffer (overloading the
existing method) makes this clearer.
The new allocateCString methods allocate the given content plus a
null-terminator character, and return a buffer covering both the string and
null-terminator. This makes them suitable for creating c-string content for
jitlink::Blocks.
Existing users of the old allocateString method have been updated to use the
new allocateContent overload.
